Assessment of biowaste potential for biogas and biofertilizer production in the Gedeo zone: a study of commercial, institutional, coffee, and wood processing industries

Organic waste is both abundant and inevitable, making anaerobic digestion an effective method for converting it into valuable resources. This study aimed to highlight the potential advantages of organic waste from the Gedeo zone as a renewable source for biofuel and biofertilizer production. The research employed a systematic and comprehensive approach, combining various data collection and sampling techniques with mathematical models based on standard assessments. The Gedeo zone produces approximately 3.8 million tons of selected biowaste annually, which could potentially yield about 133 million m(3) of biogas and 1.9 million tons of biofertilizer each year. This biogas could replace kerosene and coal for domestic cooking, reducing wood fuel consumption. Implementing an effective biogas program in Ethiopia could significantly mitigate environmental and public health issues, deforestation, and greenhouse gas emissions. A key conclusion is that biodegradable waste, being a major fraction with suitable properties for recycling, can provide economic benefits while eliminating the need for disposal.